sticking throttle/ high rpm

I have a 3.9L 5 speed 91 dakota. Sometimes when I drive hard and shift gears quick, the rpm stays high in between shifts. Usually around 2800 rpm. Have changed timing chain, plugs, idle controll motor, and cleaned the throttle body. The throttle cable is fine and nothing seem to stick when the cable is worked from under hood. I've had this problem ever since replacing the idle control motor which was noisey. When the motor is unplugged, the truck drives fine. I know it's probably the idle motor but does anyone else have this problem. When the idle motor is unplugged the idle rpm flucuates from 800 to 1100. Weird. Please help.

my first thought would be if you just replaced the iac sol, the computer could be trying to relearn ....
and hunt for the proper mixture

i would reset the computer ( revome the neg batt cable ) for abt 2 or 3 min and reconect and start it up ....let it run for a bit and then check for codes at the check engine light .